Respiratory Syncytial Virus (RSV) is a leading cause of childhood respiratory disease, responsible for 75,000? 125,000 hospitalizations annually and producing significant morbidity and economic impact. No vaccine is currently licensed to prevent RSV infections. Children hospitalized for RSV lower respiratory tract infections (LRTIs) have reduced pulmonary function, a significant predictor of adult chronic lung disease. This is a competing renewal for our P01, originally funded as AADCRC AI46004 and subsequently through two P01 cycles (9/1/2005-present). Work in our P01 has elucidated mechanisms by which RSV infection produces a rapid epithelial oxidative stress response, triggering innate signaling and resulting in cytokine secretion that triggers and shapes adaptive immunity. More recently, we have developed additional compelling evidence supporting the central theme of this P01 ? that innate inflammation produced by infection with the ubiquitous viral pathogen RSV impairs antioxidant capacity, producing disease and triggering long-term airway remodeling. Our projects are developed from original discoveries by our internationally recognized project leaders (PLs) expert in innate inflammation, oxidative stress, and the DNA damage response. Our renewal includes three major research projects (RPs): 1) RP1 (?Epigenetic regulation of innate inflammation-driven airway remodeling?) will focus on the role of the NF?B-coactivator, a chromatin remodeling complex (CRC) nucleated by bromodomain-containing protein 4 (BRD4) in RSV-induced remodeling via epithelial- mesenchymal transition and myofibroblast expansion; 2) RP2 (?The role of innate immunity in downregulation of the airway antioxidant response during paramyxovirus infection?) will focus on how RSV causes disease mediated by unbalanced ROS production via a progressive decrease in NF-E2-related factor 2 (NRF2); and 3) RP3 (?Linkage of the oxidant induced OGG1-DNA complex to airway inflammation and remodeling?) will test the hypothesis that RSV-induced epigenetic modification via oxidation of guanine to oxoG in gene regulatory regions controls acute/chronic inflammation and airway remodeling via the NF?B pathway. This P01 is guided by regular and sustained interactions with our Internal and External Advisory Committees and is nurtured by significant institutional support from UTMB Centers, Departments, and Institutes. All our inter-related and synergistic RPs are supported by an Administrative Core, and human subjects and viral preparations from the Infant Bronchiolitis and Viral Core (IBVC). Translational advances include applications of BRD4 inhibitors, NRF2 agonists, and OGG1 inhibitors that in preclinical studies show promise to interfere with RSV-induced inflammation and remodeling. Upon completion, this P01 will have identified mechanisms of innate signaling-induced remodeling and developed strategies for reversing remodeling and restoring defective innate immunity in allergic airway diseases.